Abstracted/indexed

Luminescence dating requires irradiating the sample in the laboratory. Some concerns have been published recently about the reliability of the calibration procedure. Here we have addressed these concerns. We found that the interplay between geometrical parameters such as grain size and aliquot size impact on the calibration more than previously thought. The results allow us recommending improved calibration procedure to enhance the reliability of the calibration value.

To explore the U-Pb geochronometer in fluorite, the spatial distribution of uranium and other substituted elements in natural crystals is investigated using induced fission-track and synchrotron radiation X-ray fluorescence mapping. LA-ICP-MS U-Pb dating on four crystals, that preserved micrometer-scale variations in U concentrations, yield identical ages within analytical uncertainty. Our results show that fluorite U-Pb geochronology has potential for dating distinct crystal growth stages.

We generated a synthetic dataset applying published kinetic models and distinct annealing kinetics for the apatite fission-track and (U-Th)/He methods using a predetermined thermal history. We then tested how well the true thermal history could be recovered under different data interpretation schemes and geologic constraint assumptions using the Bayesian QTQt software. Our results demonstrate that multikinetic data increase time-temperature resolution and can constrain complex thermal histories.

Here we present the foundation dataset for “TephraNZ”, a formal, comprehensive, open access, reference dataset of glass-shard compositions for New Zealand tephras. We geochemically characterise 45 eruptive episodes ranging from Kaharoa (c. 636 cal. yrs BP) to the Hikuroa Pumice member (c. 2.0 Ma) from six or more caldera sources, most from the central Taupō Volcanic Zone.

Past climate conditions have had an influence on coastal landscape dynamics in the Siberian Arctic. Coastal deposits can help to reconstruct variability and predict future changes. In this study, we show that the age of old beach shorelines can be reliably obtained by dating driftwood. This is surprising, as the wood travels long distances through large rivers. With this knowledge, the timing of past coastal change can be identified and precisely dated in marine deposits containing driftwood.

Artificial intelligence techniques are capable of detecting fission tracks automatically in minerals. The here presented AI-Track-tive software can be used to automatically determine fission track densities for apatite fission track dating studies. Apatite fission track dating is mainly applied to tectonic studies studying exhumation rates in orogens. Now, time-consuming manual track counting is replaced by deep neural networks capable of automatically finding the large majority of the tracks.

We introduce a new model of confined fission-track revelation, which simulates the etching process and accounts for variable along-track etching rates. This complete characterization explains many observations, including community difficulty in obtaining consistent track length measurements. It also provides a quantitative basis for optimizing etching procedures, and ultimately deriving more robust and reproducible fission-track ages and thermal histories.

High-resolution geochronology is one of the key factors to predict explosive volcanic eruptions. To build up high-resolution geochronology, we report 21 new high-precision 40Ar/39Ar ages for a ~3.3 million years old volcanic history on Milos, Greece. In combination with geochemical information and eruption volumes from the volcanoes of Milos, the long-lived volcanic history could provide important clues for the prediction of volcanic eruptions.

We present the results of a series of experiments that constrain the temperature sensitivity of fission tracks in monazite over geological time. It was concluded that over a heating duration of ten million years the estimated closure temperature is < 50 °C and perhaps not much above ambient surface temperatures. Monazite fission track thermochronology has the potential to understand the thermal history of the Earth's upper crust (< 1–2 km) and constrain the timing of geological processes.

This paper describes GeoChronR, an R package that streamlines the process of quantifying age uncertainties, propagating uncertainties through several common analyses, and visualizing the results. In addition to describing the structure and underlying theory of the package, we present five real-world use cases that illustrate common workflows in GeoChronR. GeoChronR is built on the Linked PaleoData framework, is open and extensible, and we welcome feedback and contributions from the community.

In this study, we built a statistical model to determine the initial δ²³⁴U in submerged calcite crusts that coat the walls of Devils Hole 2 (DH2) cave (Nevada, USA) and, using ²³⁴U-²³⁸U dating method, extended the chronology of the calcite depostion beyond the previous well-established ²³⁰Th ages, and determined the oldest calcite deposited in this cave, a time marker for cave genesis. The novel method presented here may be used in future speleothem studies in similar hydrogeological settings.

Orakei Basin, a former maar lake in Auckland, New Zealand provides an outstanding sediment record over the last ca. 130,000 years but an age model is required to allow the reconstruction of climate change and volcanic eruptions contained in the sequence. To construct a relationship between depth in the sediment core and age of deposition, we combined tephrochronology, radiocarbon dating, luminescence dating, and the relative intensity of the paleomagnetic field in a Bayesian age-depth model.

This contribution present a new reference material, ASH-15 flowstone with an age of 2.965 ± 0.011 Ma (2σ), to be used for in-situ U-Pb dating of carbonate material. The new age analyses include the use of the EARTHTIME isotopic tracers and a large number of sub-samples (n = 36) with small aliquots (1–7 mg) each that are more representative of laser-ablation spot analysis. The new results could improve the propagated uncertainties on the final age with a minimal value of 0.4 %.

Unetched and etched apatites of five samples were dated by U–Pb with laser ablation inductively coupled plasma mass spectrometry. Our experiment demonstrates that the etching, needed for the apatite fission track dating, has no important effect on the obtaining of U–Pb ages; and therefore, the laser ablation-based technique can be used for apatite fission track and U–Pb double dating.

We characterize three natural carbonate samples with elevated uranium/lead (U/Pb) ratios to demonstrate techniques for characterizing carbonates for U/Pb dating. With the rapidly accelerating application of laser ablation analyses, there is a great need for well-characterized standards. The three samples we describe have good potential as standards. In addition to U/Pb data, we present strontium (Sr) isotope analyses to demonstrate that these could be dual standards for U/Pb and Sr isotopes.

Potassium-based geochronology, including the ⁴⁰Ar/³⁹Ar and K-Ar methods, provides critical constraints on the timing and duration of many events and processes in earth history. These methods assume that a key parameter, the fraction of potassium with a mass of 40, does not vary in some relevant materials. Some recent work has identified some variability in these materials. This work examines the effects of this variability on calculated K-Ar and ⁴⁰Ar/³⁹Ar ages.

The North American Varve Chronology is a sequence of 5659 annual sedimentary layers that were deposited in proglacial lakes adjacent to the retreating Laurentide Ice Sheet ca. 12,500 - 18,200 years ago. We attempt to synchronize this record with Greenland ice core and other climate records that cover the same time period by detecting variations in global fallout of atmospherically-produced beryllium-10 in NAVC sediments.

We compare two published U-Pb and ⁴⁰Ar/³⁹Ar geochronologic datasets used to produce different eruption rate models for the Deccan Traps LIP. We conclude that differences in eruption rates arise not from inaccuracy of dates, but instead from the way the data were presented. Applying the same statistical approach to each dataset, the resulting models agree well, but the higher precision U-Pb dataset generates a more nuanced eruption model that is untestable with the lower precision ⁴⁰Ar/³⁹Ar data.

Meteoric Beryllium-10 concentrations in soil profiles have great capacity to quantify earth surface processes, such as erosion rates and landform ages. However, determining these requires an accurate estimate of the delivery rate of this isotope to local sites. We present a new method to constrain the long-term delivery rate to a western US site and then compare it against existing delivery rate estimates, revealing considerable disagreement between methods, and suggest best practices.

A new methodology for the micron-scale uranium-lead dating of carbonate minerals is proposed. It is based on the extraction of ages directly from the pixels images (< 1 mm²) obtained by laser ablation coupled to a mass spectrometer. The ages are calculated with a robust linear regression through the pixel values, which is an efficient and simple approach to that can be easily applied to mineral dating.

Cassiterite is the primary ore mineral of tin and is associated with lots of other elements we need for green technology. It is deposited from fluids that are released from magmas. Because it is extremely acid resistant there has been difficulty in dissolving the mineral for analysis, we use a novel method to dissolve and extract radiogenic isotopes of the uranium to lead decay scheme from Cassiterite and analyse its age thus improving the ability to work out the formation processes.